From: Rob Herring <robh@kernel.org>
To: Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Jiri Olsa <jolsa@redhat.com>,
Kan Liang <kan.liang@linux.intel.com>,
Ian Rogers <irogers@google.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
honnappa.nagarahalli@arm.com, Zachary.Leaf@arm.com,
Raphael Gault <raphael.gault@arm.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Namhyung Kim <namhyung@kernel.org>,
Itaru Kitayama <itaru.kitayama@gmail.com>,
Vince Weaver <vincent.weaver@maine.edu>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v10 2/5] perf: Add a counter for number of user access events in context
Date: Tue, 14 Sep 2021 15:47:57 -0500 [thread overview]
Message-ID: <20210914204800.3945732-3-robh@kernel.org> (raw)
In-Reply-To: <20210914204800.3945732-1-robh@kernel.org>
For controlling user space counter access, we need to know if any event
in a context (currently scheduled or not) is using user space counters.
Walking the context's list of events would be slow, so add a counter
to track this.
Signed-off-by: Rob Herring <robh@kernel.org>
---
v10:
- Re-added.
- Maintain the count in the perf core
v9:
- Dropped
v8:
- new patch
---
include/linux/perf_event.h | 1 +
kernel/events/core.c | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 12debf008d39..4f82a4d47139 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -821,6 +821,7 @@ struct perf_event_context {
int nr_events;
int nr_active;
+ int nr_user;
int is_active;
int nr_stat;
int nr_freq;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 744e8726c5b2..01290d150da3 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1808,6 +1808,8 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx)
list_add_rcu(&event->event_entry, &ctx->event_list);
ctx->nr_events++;
+ if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT)
+ ctx->nr_user++;
if (event->attr.inherit_stat)
ctx->nr_stat++;
@@ -1999,6 +2001,8 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
event->attach_state &= ~PERF_ATTACH_CONTEXT;
ctx->nr_events--;
+ if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT)
+ ctx->nr_user--;
if (event->attr.inherit_stat)
ctx->nr_stat--;
--
2.30.2
next prev parent reply other threads:[~2021-09-14 20:48 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-14 20:47 [PATCH v10 0/5] arm64 userspace counter support Rob Herring
2021-09-14 20:47 ` [PATCH v10 1/5] x86: perf: Move RDPMC event flag to a common definition Rob Herring
2021-10-13 17:25 ` Mark Rutland
2021-09-14 20:47 ` Rob Herring [this message]
2021-10-13 17:26 ` [PATCH v10 2/5] perf: Add a counter for number of user access events in context Mark Rutland
2021-09-14 20:47 ` [PATCH v10 3/5] arm64: perf: Add userspace counter access disable switch Rob Herring
2021-10-13 17:30 ` Mark Rutland
2021-09-14 20:47 ` [PATCH v10 4/5] arm64: perf: Enable PMU counter userspace access for perf event Rob Herring
2021-10-14 16:58 ` Mark Rutland
2021-10-14 19:24 ` Rob Herring
2021-10-19 15:28 ` Mark Rutland
2021-10-15 15:53 ` Rob Herring
2021-09-14 20:48 ` [PATCH v10 5/5] Documentation: arm64: Document PMU counters access from userspace Rob Herring
2021-09-27 20:46 ` [PATCH v10 0/5] arm64 userspace counter support Rob Herring
2021-10-13 17:32 ` Mark Rutland
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210914204800.3945732-3-robh@kernel.org \
--to=robh@kernel.org \
--cc=Jonathan.Cameron@huawei.com \
--cc=Zachary.Leaf@arm.com \
--cc=acme@kernel.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=catalin.marinas@arm.com \
--cc=honnappa.nagarahalli@arm.com \
--cc=irogers@google.com \
--cc=itaru.kitayama@gmail.com \
--cc=jolsa@redhat.com \
--cc=kan.liang@linux.intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=raphael.gault@arm.com \
--cc=vincent.weaver@maine.edu \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).